I went to rock auto to order and I get two choices depending on the engine built date. Ford came out with a new gasket and torque specs because the gaskets failed and coolant leaked into the engines combustion chambers and in the oil. So I am confused in which one to order. The one dated January 15, 1998, and later or before which was the defective ones. It says one is 3mm and the other 4mm. Why would they still have the defective one as a choice?

 

The engine in question was built January 5, 1998. Thanks to anyone who can help!